BATAVIA  It probably would not be cause for alarm, but certainly will arouse curiosity come Tuesday, when residents and motorists in and around Miami and Union townships in Clermont County start seeing a large balloon overhead.

The balloon is flown over proposed sites of water-storage tanks at fixed heights, then photographed from the ground so engineers can superimpose a storage tank on the photo, giving engineers and residents an idea of what the tank would look like from various angles along the ground.

Without the balloon, you're just guessing at elevation or size of the tank, said Mr. Jaehnen, of the Clermont County Water and Sewer District.

The district plans to build nine storage tanks over the next 10-15 years in western Clermont County. The first, in Miami Township, should be in operation in August.

Construction has begun on another, but the other seven are only in planning stages.

The storage tanks enhance fire protection, provide storage during peak demand times and provide water during power outages.

Tom Yeager, utilities director for the county, said the tanks are being built in western Clermont because of the tremendous growth in the past 10 years.

The district plans to hold a series of public meetings over the next few years to get residents' opinions before the storage tanks are constructed.

That's where the photographs come in. Mr. Jaehnen said photos will be taken from roads and even peoples' yards up to a half-mile away.

If it's really obtrusive to people, then we're going to look at other options, said Mr. Jaehnen.

The balloon is about 10 feet tall and 6 feet wide. It is filled with helium.